Natural History and Risk Stratification of Biochemically Recurrent Prostate Cancer Following Definitive Radiation...

Among patients with biochemical recurrent (BCR) prostate cancer following radiation therapy, there is no validated method for identifying those at the highest risk for metastases or death from prostate cancer. We characterized the natural history of BCR after radiation therapy and validated the proposed European consensus guidelines for stratification.

This retrospective, multicenter, nationwide cohort study used data from patients having postradiation BCR treated in the United States Veterans Administration Health System. High-risk BCR was defined as either Gleason score ≥8 or BCR occurring within 18 months of radiation therapy, per guidelines.

Among 7126 patients who experienced BCR, 35.5% of patients developed metastatic disease and 17.4% died of prostate cancer at 10 years. 38.5% of patients had a high-risk BCR. High-risk BCR resulted in higher 10-year incidence of metastatic disease (56.2% vs 42.0%, adjusted hazard ratio [aHR] = 1.83, 95% CI: 1.69-1.98) and worse prostate cancer-specific survival (69.5% vs 81.6%, aHR = 1.82, 95% CI: 1.63-2.03, P < .001) and all-cause death (67.8% vs 65.0%, aHR = 1.18, 95% CI: 1.11-1.26, P < .001).

A simple, 2-element risk stratification tool using existing clinical data is the first validated tool for identifying patients at risk of metastases or prostate cancer-specific mortality following postradiation BCR. Most patients experiencing BCR in this context do not develop metastases or lethal prostate cancer, making such stratification essential for treatment decision-making and refinement of patient populations for clinical trials.